The present invention is directed to a method and a device for clarifying liquids and in particular to a method and a device for separating particles from a mixture of particles and liquid.
Liquids, such as water, often contain undesired substances such as suspended solids or organic matter, hereinafter referred to generally as particles. When the particles have a greater specific gravity than the specific gravity of the carrier liquid, such particles may be separated from the liquid mixture to form clarified liquid by gravitational settling of the particles. Clarifying devices have been used in the treatment of water and wastewater for the gravitational settling and separation of particles from liquid due to differences in specific gravity. In some cases, where the particles are fine in size, the particles may not settle and may remain in suspension within the liquid. Flocculation is used to effectively agglomerate very fine particles into larger and heavier particles and thus increase their rate of settling or separation from the liquid. Flocculation is a process of bringing together fine particles so that they agglomerate as floc particles. In some cases, fine suspended particles are stable and will not agglomerate without chemical treatment to destabalize them so that they will stick together when flocculated. Chemical additives such as coagulants may be added to the liquid mixture to aid in flocculation.